JP4405204B2 - Method for forming rubber beads of metal rubber gasket - Google Patents

Description

  The present invention relates to a cylinder head gasket that is inserted between a cylinder block and a cylinder head opposed to each other in an internal combustion engine used in, for example, motorcycles, automobiles, industrial machines, outboard motors, and the like, and seals between the joint surfaces. The present invention relates to a method for forming a rubber bead constituting the metal rubber gasket.

The applicant of the present application invented the gasket described in Japanese Patent Application No. 2002-102437 (unpublished) as a metal rubber gasket having excellent sealing performance.
In this metal rubber gasket, as shown in FIGS. 12 and 13, the substrate 11 is made of one thin steel plate, and the first thickened portion A is formed by folding the entire circumference of the combustion chamber hole opening end portion 12. At the same time, a part of the outer peripheral edge of the substrate 11 is folded back to form the second thickened portion C, and the beads 14 and 15 are formed along the seal lines that need to be sealed. The bead includes a full bead or a half bead-shaped metal bead obtained by bending the substrate in the plate thickness direction, and an elastic sealing material 24 and a convex part that fix the metal bead to the surface of the convex part of the metal bead so as to have substantially the same height. And a rubber bead made of an elastic sealing material 24 filled in the recess on the back side.
The rubber beads fixed to both surfaces of the metal beads are produced by molding. For example, if a small hole 21 is formed on the R surface of the metal bead and a fluid elastic sealing material is injected from one of the surfaces during rubber bead molding, the other surface side of the metal bead is passed through the small hole 21. In addition, an elastic sealing material is injected and filled, and rubber beads are formed on both sides of each metal bead.
Japanese Patent Application No. 2002-102437 (unpublished)

In the rubber bead molding method described above, it is injected into the rubber bead molding gap (the rubber bead molding gap formed between the board and the mold) on either the upper or lower surface of the uneven metal bead to be molded on the board. In this case, the metal beads are injected into the upper and lower sides of the metal beads through the small holes 21 formed in the R part. However, when there are a large number of independent bead lines, it is necessary to set the injection port for each independent bead. There is.
In addition, if a large number of small holes 21 are formed in the metal bead as described above, the strength of the metal bead may be reduced and the metal bead may be deformed by high pressure when the elastic sealing material is injected. Further, when the produced metal rubber gasket is attached between the opposing joining surfaces, if it is strongly tightened for the purpose of increasing the sealing pressure, the elastic sealing material in the metal bead recess passes through the small hole 21 formed in the metal bead. There is also a possibility that the surface pressure is lowered by being deformed and moved to the convex side.
This invention pays attention to the above points, and makes it a subject to provide the rubber bead molding method of the metal rubber gasket which can shape | mold a rubber bead more simply.

In order to solve the above problems, the invention described in claim 1 of the present invention, a thin metal plate and the substrate, a plurality openings that gas or liquids to the substrate to form a hole or a bolt hole circulating A plurality of beads are formed so as to extend so as to surround the outer periphery of the opening that needs to be sealed, and each of the beads is bent in the plate thickness direction and formed into a convex shape on one surface side. And a rubber bead made of an elastic sealing material that is fixed to the convex portion side surface of the metal bead and is filled in a concave portion on the back side of the convex portion and is compressively deformed in the thickness direction along with the deformation of the metal bead. A method for forming the rubber beads in a metal rubber gasket composed of a combination,
The rubber bead is molded by inserting the substrate on which the metal bead is molded into upper and lower molds for molding a rubber bead, and injecting a fluid elastic seal material into a gap for molding the rubber bead between the metal bead and the mold. In the method of molding
With respect to the said board | substrate, between the recessed parts of the independent metal bead was made to communicate with the 2nd metal bead of a full bead whose convex part height is lower than the said metal bead, and became independent through the inside of the recessed part of the 2nd metal bead. Allows circulation of elastic sealing material between recesses in metal beads ,
The second metal bead communicates with an opening provided in the substrate, and the opening serves as an injection portion for an elastic seal material .

According to the present invention, the inside of the recess of the independent metal bead communicates with the recess of the second metal bead. As a result, if the elastic sealing material is injected into the gap for rubber bead molding on the recess side of one bead, The elastic sealing material can be injected and filled in the voids for molding the other bead rubber beads.
In addition, a second metal bead (an elastic sealant is filled in the recess) is formed on the substrate, but the height of the protrusion is lower than the original metal bead formed along the bead, It is prevented that the seal surface pressure of the original bead due to the second metal bead is lowered.

In addition, by using the opening as the injection part, it is possible to inject the elastic sealing material on both surfaces of the substrate without forming the small holes 21 in the metal bead.

Next, the invention described in claim 2, the thin metal plate to a substrate, opening a gas or a liquid material to the substrate to form a hole or a bolt hole for circulation provided with a plurality of outer periphery of the seal is required aperture A plurality of beads are formed so as to extend so as to surround the metal beads, and each of the beads includes a metal bead formed by bending the substrate in a plate thickness direction and forming a convex shape on one surface side, and the metal bead. In a metal rubber gasket composed of a combination of a rubber bead made of an elastic seal material that is fixed to the surface of the convex portion and filled in a concave portion on the back side of the convex portion and compressively deforms in the thickness direction along with the deformation of the metal bead. A method for molding the rubber beads,
The rubber bead is molded by inserting the substrate on which the metal bead is molded into upper and lower molds for molding a rubber bead, and injecting a fluid elastic seal material into a gap for molding the rubber bead between the metal bead and the mold. In the method of molding
For distribution of the inner surface of the mold facing the substrate surface between the individual metal bead convex side surfaces so as to communicate the gaps for rubber bead molding on the individual metal bead convex side surface side The groove depth is set lower than the height of the convex portion of the metal bead ,
The distribution groove communicates with an opening opened in the substrate, and the opening serves as an injection portion for an elastic sealing material .

According to the present invention, as a result of the gap on the convex portion side of the independent metal bead communicating with the above-mentioned groove for circulation, if an elastic sealing material is injected into the void for rubber bead molding on the convex portion side of one bead, The elastic sealing material can be injected and filled into the gap for rubber bead molding of other independent beads.
Also, the groove-shaped rubber beads are formed on the substrate, but the convex bead height is lower than the metal beads formed along the beads. It is possible to prevent the seal surface pressure from being lowered. In particular, since a rubber bead having a groove shape has a metal bead inside, the pressure generated even when it is compressed and deformed is small.

In addition, by using the opening as the injection portion, it is possible to inject the elastic sealing material on both surfaces of the substrate without forming a small hole in the metal bead.

Next, the invention described in claim 3, compared arrangement according to claim 1 or claim 2, at least a portion of the mold inner surface facing the convex portion the top of the metal bead, convex portion of the metal bead By providing a recess on the inner surface of the mold so that a gap is formed between the top and the top, the elastic sealing material can be distributed across the top of the protrusion of the metal bead. .
Here, in this invention, after rubber bead shaping | molding, a partial bulge is formed in a part of rubber bead. The bulge may be formed so as to have a gentle slope along the extending direction of the top of the bead, or may be swelled so as to have a gentle slope along the R of the metal bead.

Next, the invention described in claim 4, compared structure according to any one of claims 1 to 3, by forming a recess in at least a portion of the protrusion top of the metal bead, facing A gap is formed between the inner surface of the mold and the convex top of the metal bead so that the elastic sealing material can be distributed across the convex top of the metal bead.
Here, the invention according to claim 4 and the invention according to claim 3 may be used in combination to form a concave portion on the mold side and a concave portion of the metal bead at opposing portions. In this case, as a result of the height of the convex portion of the metal bead being lowered by the bulge of the rubber bead according to the invention of claim 3 , the seal surface pressure of that portion is made the same as the seal surface pressure of the other portion. Easy to set.

  According to the present invention, it is possible to efficiently form a rubber bead on a metal bead from a small number of injection ports without providing small holes in the metal bead.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of an essential part showing an example of a metal rubber gasket according to an embodiment of the present invention. First, the configuration of this metal rubber gasket will be described.
A substrate 2 is composed of a thin metal plate such as a stainless steel plate or a mild steel plate, and a plurality of openings such as a combustion chamber hole 3, a water hole 4, an oil hole 6, and a bolt insertion hole 5 are formed on the substrate 2 in accordance with the purpose. Has been.

  The entire circumference of the end portion of the substrate 2 on the combustion chamber hole 3 side is folded upward to form the thickest first thickened portion 7. Thereby, the plate | board thickness difference is provided between the other parts. The edge on the outer peripheral side of the substrate 2 is also partially folded upward to form the second thickened portion 12. The second thickened portion 12 is set to be thinner than the first thickened portion 7 by forging or the like. Here, the first thickened portion 7 and the second thickened portion 12 are formed after a bead composed of metal beads 10 and 11 and rubber beads (20a and 20b) described later is formed along the seal lines SL1 and SL2. Processed.

  The thickness of the first thickened portion 7 is designed to be thin in the vicinity of the bolt insertion hole 5, and is designed to be thick between the bolt insertion holes 5, along the circumferential direction of the combustion chamber hole 3. The plate thickness is changed (inflated) so that the surface pressure by the first thickened portion 7 along the circumferential direction after bolt tightening is equalized. Further, the thickness of the first thickened portion 7 at the thin position is set to be thicker than the thickest thickness of the second thickened portion 12.

  Further, among the openings, seal lines SL1 and SL2 are set so as to surround an outer periphery of an opening such as a combustion chamber hole that needs to be sealed, and seal lines SL1 and SL2 are set along the outer periphery of the substrate 2. In addition, seal lines SL1 and SL2 are set as necessary. The seal lines SL1 and SL2 shown in FIG. 1 are examples, and the present invention is not limited to these.

In this way, a plurality of independent seal lines SL1 and SL2 are set in accordance with the purpose, and beads are provided independently along the seal lines SL1 and SL2. As shown in FIG. 2 which is a DD cross section of FIG. 1, each bead includes metal beads 10, 11 formed by bending the substrate 2 in the plate thickness direction so as to be convex upward, and the metal beads 10, 11, 11 and a rubber bead composed of elastic sealing materials 20a and 20b that are fixed to the surface of the convex portion and filled in the concave portion on the back side of the convex portion.
The metal beads 10 and 11 are set slightly higher than the height of the thickened portion, so that they can be elastically deformed in the plate thickness direction when the bolts are tightened. For example, the height of the convex portion of the metal bead 10 near the first thickened portion 7 is slightly higher than that of the first thickened portion 7, and the height of the convex portion of the metal bead 11 near the second thickened portion 12 is the first height. 2 Slightly higher than the thickened portion 12.

  Further, the rubber bead will be described. The elastic sealing material 20 a filled in the concave portion on the back side of the convex portion of the metal beads 10 and 11 is set so as to be flush with the lower surface of the substrate 2. In addition, the elastic sealing material 20 b fixed to the convex surface of the metal beads 10, 11 is set so that the height thereof is substantially equal to that of the convex portions of the metal beads 10, 11. The elastic seal material 20b on the convex side is formed substantially symmetrically on both sides of the top portions 10a and 11a of the convex portions of the metal beads 10 and 11. Here, the elastic sealing materials 20a and 20b are made of, for example, a rubber material or a resin material having good fluidity such as fluoro rubber, NBR, or silicone rubber, and have elasticity and heat resistance.

The rubber beads made of the elastic sealing materials 20a and 20b are formed before the metal beads 10 and 11 are formed and the first and second thickened portions 7 and 12 are formed.
That is, after processing the substrate 2 and forming the metal beads 10 and 11 along the seal lines SL1 and SL2, the substrate 2 on which the metal beads 10 and 11 are formed is interposed in upper and lower molds (not shown). To do. At this time, rubber-bead-shaped voids on the convex portion side are formed between the inner surface (lower surface) of the upper mold and the convex surfaces of the metal beads 10 and 11 on the upper surface of the substrate 2. Further, a recess for forming a rubber bead on the recess side is formed between the inner surface (upper surface) of the lower mold and the recess surface on the back side of the protrusion of the metal beads 10 and 11.

The injection method (molding method) of the elastic sealing materials 20a and 20b according to the present embodiment is a technique for forming the number of the sealing materials as small as possible within a range in which the number of injection ports 8 is as small as possible and does not affect the gasket performance.
First, the injection port 8 is set in the vicinity of the center portion of the substrate 2 and in the portion of the substrate 2 where the metal beads 10 and 11 are not formed. The injection port 8 may be formed only for injection of the sealing material, but it is preferable to use an existing opening such as a water hole or a bolt hole.

  As shown in FIG. 3 which is a plan view, the surface of the substrate 2 between the injection port 8 and each of the metal beads 10 and 11 (planar portion) so as to connect the two independent metal beads 10 and 11 and the injection port 8. In the lower surface of the upper mold opposite to the upper mold), grooves extending to the positions of the injection port 8 and the metal beads 10, 11 are provided. In FIG. 3, the portion indicated by the alternate long and short dash line A is the groove forming position. Here, FIG. 4 shows a state after the rubber bead and the thickened portion are formed. The elastic sealing material indicated by reference numeral 31 in FIG. 4 is an elastic sealing material portion formed by the groove.

  In addition, the second metal bead 32 made of an upward convex full bead extending from the inlet 8 to the positions of the metal beads 10 and 11 with respect to the substrate 2 so as not to overlap the groove position in plan view. Is formed. The second metal bead 32 is set to have a convex portion height lower than that of the metal beads 10 and 11 by setting the convex portion height below the height of the thickened portion. FIG. 5 shows a state after the rubber bead and the thickened portion are formed. The elastic sealing material indicated by reference numeral 33 in FIG. 5 is an elastic sealing material portion filled in the second metal bead 32.

  Thereby, the fluid elastic sealing materials 20a and 20b injected from the injection port 8 are injected into the recesses of the two independent metal beads 10 and 11 through the recesses of the second metal bead 32, and continue. Then, the elastic seal members 20a and 20b are filled in the concave portions of the metal beads 10 and 11 communicating with the concave portions of the metal beads 10 and 11, respectively. Thus, the elastic seal members 20a and 20b are filled in the gaps on the back side of the convex portion, and the rubber beads on the concave portion side are formed.

  At the same time, the fluid elastic sealing materials 20a and 20b injected from the injection port 8 pass through a flow path formed between the circulation groove (groove formed in a mold not shown) and the surface of the substrate 2. Metal beads 10 that are injected into the gaps on the convex side of the two independent metal beads 10 and 11 (gap on the surface of the convex part on the injection port 8 side) and communicate with the gaps on the convex side of each metal bead 10 and 11. 11 are filled with elastic sealing materials 20a and 20b.

  Here, the number of the injection ports 8 is not limited to one, and a plurality of injection ports may be provided. In addition, when the seal lines SL1 and SL2 are long and there is a concern that the elastic sealing materials 20a and 20b are vulcanized while moving in the hot mold, the above-described metal beads 10 and 11 are appropriately connected with each other. The injection time is shortened by communicating with the second metal bead 32 as described above or a flow channel formed in the mold. For example, as shown in FIG. 6 which is a BB cross-sectional view after forming, the adjacent positions of the independent metal beads 10 and 11 are connected by the second metal bead 32.

  Further, the rubber bead molding gap on the convex side of the metal beads 10 and 11 is separated on both sides with the top parts 10a and 11a of the metal beads 10 and 11 as a boundary, and the one gap on the convex side is elastic. Even if the sealing materials 20a and 20b are injected, the elastic sealing materials 20a and 20b are not easily injected into the other gap between the top portions 10a and 11a. For this reason, it is necessary to separately provide an inlet for the other gap sandwiching the top portions 10a and 11a. However, in this embodiment, the other gap sandwiching the top portions 10a and 11a is also provided without providing an additional inlet. A configuration in which the elastic sealing material flows in is adopted.

That is, either of the following two is adopted as means for injecting the sealing material into both the entrance side and the opposite side of the convex side gap.
In the first method, as shown in FIG. 7 and FIG. 8, partial recesses are formed so that the height of the protrusions is lower than the other portions in a part in the extending direction of the metal beads 10 and 11. As a result, a gap is formed between the upper mold and the convex surfaces of the metal beads 10 and 11 so as to straddle the top portions 10a and 11a, and the gap is secured as a flow path. 7 shows that the top portions 10a and 11a are partially flattened to form the above-mentioned concave portion, and the one shown in FIG. 8 is gradually along the extending direction of the metal beads 10 and 11. This is an example in which a partial concave portion is formed by reducing the height of the convex portion. In addition, since the part in which the said recessed part was formed may have a relatively low surface pressure, it is preferable to provide in the part with a large surface pressure at the time of bolt fastening in seal line SL1, SL2.

  Further, as shown in FIG. 9 and FIG. 10, the second method is to form a recess in a part of the upper mold inner surface (lower surface) facing the top portions 10a, 11a of the metal beads 10, 11 to form the top portions 10a, 11a. It is intended to secure a crossing flow passage. FIG. 9 shows an example in which a concave portion along the convex portion R of the metal beads 10 and 11 is formed. In FIG. 10, a concave portion is formed so as to form a gentle inclined surface along the longitudinal direction of the metal beads 10 and 11. In addition, since the height of the rubber bead portion of the portion where the concave portion is formed is partially increased (see 10a and 11a), the concave portion is formed in the portion where the surface pressure is reduced when the bolt is tightened along the seal lines SL1 and SL2. Is preferably set. In some cases, both the first and second methods may be employed for the same position to cancel the increase or decrease in surface pressure.

Specifically, the second method of the latter is adopted when the engine has rigidity and high pressure is sealed, and the former method is adopted when the sealing pressure is low in an engine without rigidity. good.
Moreover, although the case where the metal beads 10 and 11 are full beads is shown in the above example, half beads may be used as shown in FIG. In FIG. 11, the case where the 2nd metal bead 32 is formed and the flow path is ensured is illustrated.

And after shape | molding a rubber bead by the said method, the above-mentioned thickened part is formed.
When the rubber bead forming method as described above is employed, the sealing material injected from the injection port 88 can be injected simultaneously from one injection port 8 to the entire circumference of the concave surface of the bead and the entire circumference of both sides of the convex side bead. By increasing the number of second metal beads 32 and grooves 30 that connect them, an injection time can be shortened and an efficient and resource-saving inexpensive gasket can be provided.

  In addition, since the elastic sealing material 31 formed by the second metal beads 32 and the grooves is set lower than the metal beads 10 and 11, the elastic sealing material 31 by the second metal beads 32 and the grooves is formed on the substrate. Even if it is molded, a decrease in the sealing pressure can be suppressed. It is preferable that the height of the elastic sealing material 31 by the second metal bead 32 and the groove is not more than the height of the first thickened portion.

It is a principal part top view for demonstrating the metal rubber gasket which is an example of embodiment of this invention. It is DD sectional drawing of FIG. It is a principal part top view which shows the relationship between an injection port and each metal bead. It is a figure at the time of providing a flow path in the bead convex side by EE sectional drawing of FIG. It is a figure at the time of providing a flow path in the bead concave side by FF sectional drawing of FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is CC sectional drawing of FIG. 1 of another example. It is CC sectional drawing of FIG. 1 of another example. It is the figure which formed the bulge along the line of a bead top part, and ensured the sealing material flow path on both convex bead surfaces. It is a figure which shows the case where a metal bead is a half bead shape. It is explanatory sectional drawing for demonstrating the metal rubber gasket of a prior art. It is explanatory sectional drawing for demonstrating the metal rubber gasket of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal rubber gasket 2 Substrate 3 Combustion chamber hole 4 Water hole 5 Bolt insertion hole 6 Oil hole 7 Thickening part 8 Sealing material inlet 10 Metal bead 10a Top part 11 Metal bead 11a Top part 12 Second thickening part 20a Recessed part Elastic seal material 20b on the convex side elastic seal material 20c on the convex side bulging portion 31 of the elastic seal material elastic seal material 32 in the groove second metal bead 33 elastic seal material SL1 in the second metal bead Seal on the opening side Line SL2 Groove position on the outer peripheral seal line A type

Claims (4)

The thin metal plate to a substrate, opening a gas or a liquid material to the substrate to form a hole or a bolt hole for circulation provided with a plurality, the plural rows of beads to extend so as to surround the outer periphery of the seal is required aperture Each of the beads is formed with a metal bead formed by bending the substrate in the thickness direction and forming a convex shape on one surface side, and is fixed to the convex side surface of the metal bead and the convex portion. A rubber bead molding method in a metal rubber gasket composed of a combination of an elastic seal material filled with a recess on the back side and compressively deformed in the thickness direction along with deformation of the metal bead,
The rubber bead is molded by inserting the substrate on which the metal bead is molded into upper and lower molds for molding a rubber bead, and injecting a fluid elastic seal material into a gap for molding the rubber bead between the metal bead and the mold. In the method of molding
With respect to the said board | substrate, between the recessed parts of the independent metal bead was made to communicate with the 2nd metal bead of a full bead whose convex part height is lower than the said metal bead, and became independent through the inside of the recessed part of the 2nd metal bead. Allows circulation of elastic sealing material between recesses in metal beads ,
The method of forming a rubber bead for a metal rubber gasket , wherein the second metal bead communicates with an opening provided in the substrate, and the opening serves as an injection portion for an elastic sealing material . The thin metal plate to a substrate, opening a gas or a liquid material to the substrate to form a hole or a bolt hole for circulation provided with a plurality, the plural rows of beads to extend so as to surround the outer periphery of the seal is required aperture Each of the beads is formed with a metal bead formed by bending the substrate in the thickness direction and forming a convex shape on one surface side, and is fixed to the convex side surface of the metal bead and the convex portion. A rubber bead molding method in a metal rubber gasket composed of a combination of an elastic seal material filled with a recess on the back side and compressively deformed in the thickness direction along with deformation of the metal bead,
The rubber bead is molded by inserting the substrate on which the metal bead is molded into upper and lower molds for molding a rubber bead, and injecting a fluid elastic seal material into a gap for molding the rubber bead between the metal bead and the mold. In the method of molding
For distribution of the inner surface of the mold facing the substrate surface between the individual metal bead convex side surfaces so as to communicate the gaps for rubber bead molding on the individual metal bead convex side surface side The groove depth is set lower than the height of the convex portion of the metal bead ,
The method of forming a rubber bead for a metal rubber gasket, wherein the circulation groove communicates with an opening opened in the substrate, and the opening serves as an injection portion for an elastic sealing material . By providing a recess on the inner surface of the metal bead so that a gap is formed between at least a part of the inner surface of the mold facing the top of the convex portion of the metal bead and the convex top of the metal bead. The method for molding a rubber bead for a metal rubber gasket according to claim 1 or 2 , wherein the elastic sealing material can be distributed across the top of the convex portion of the bead. By forming a recess in at least a part of the convex top of the metal bead, a gap is formed between the opposing mold inner surface and the convex top of the metal bead, and straddles the convex top of the metal bead. claim 1 rubber bead molding method of metal rubber gasket according to any one of claims 3, characterized in that the elastic sealing material can flow.

Images